Shoe flexing device



June 19, 1962 H. LINCORS 3,039,207

SHOE FLEXING DEVICE Filed Sept. 16, 1955 5 Sheets-Sheet 1 INVENTOR.HARRY LINCORS ATTORNEY June 19, 1962 H. LINCORS 3,039,207

SHOE FLEXING DEVICE Filed Sept. 16, 1955 s Sheets-Sheet z INVENTOR.HARRY LINCORS MQ1W ATTORNEY June 19, 1962 H. LINCORS 3,0 7

SHOE FLEXING DEVICE Filed Sept. 16, 1955 s Sheets-Sheet s INVENTOR.HARRY LINCORS ATTORNEY United States Patent 3,039,207 SHOE FLEXINGDEVICE Harry Lincors, Clayton, Mo. Filed Sept. 16, 1955, Ser. No.534,639 11 Claims. (Cl. 36-585) This invention relates to shoes and,more specifically, to a shoe construction in which foot pressuresapplied in walking are converted into forces which flex the shoe intoconformity with the foot throughout each step.

This application is a continuation in part of my prior copendingapplication serial number 423,344 filed April 15, 1954 for Shoe FlexingDevice now abandoned.

By way of explanation, this movement of the shoe with respect to thefoot is perhaps best illustrated by the action of a scuff. During astep, it will be quite apparent that the foot flexes as the pressure onthe heel of the foot is transferred to the ball of the foot. Because inthe case of a scuff there is no force tending to flex the sole, the heelof the scuff remains stationary temporarily as the heel of the foot israised. When the whole foot is raised, however, the foot unflexes, andthe heel of the scuif slaps the undersurface of the foot. This repeatedslapping action is obviously undesirable from the comfort stand pointand detracts from the scope of customer appeal for certain shoe stylessuch as sling, halter sling, or strap pumps, sandals, or mules.Obviously, also, there are certain types of feet which cannot beproperly fitted in shoes without counters because, as is readilyapparent, when the heel of the foot is raised, the resistance of theshoe to flexing is a sufficient force to slip the sling straps from theheel of the foot even if the shoe is quite flexible.

The present invention applies to shoes constructed with a heel portionand a toe portion (including the forward sole portion) which areinterconnected by a flexible part, usually adjacent the ball of thefoot. According to this invention, the shoe construction incorporates adevice connected between the toe portion and the heel portion of theshoe, providing, incidentally, a cushioned support for the foot, and istensioned by pressure on or near the ball of the foot. This tension istransmitted through an interconnection to the heel portion tending toflex the shoe when pressure exerted on the heel portion of the shoe isremoved, so that the tension transmitted to the heel portion of the shoecauses it to raise and follow the heel of the foot. It is contemplatedthat this device can have many different forms, some of which are shown,but, according to this invention, however, each form is responsive topressure to place it or part of it under tension so as to exert thedesired direction and degree of force on the heel portion of the shoe tolift the heel when the pressure exerted by the heel of the foot isremoved. I

It is the object of the present invention to eliminate the slapping ofthe shoe on the heel by modifying present shoe construction to addthereto a device to flex the shoe so as to maintain contact with theheel of the foot at least during that part of the step when the pressureis being applied to the shoe by the ball of the foot.

It is also an object of the invention to provide a device for the abovepurpose which is wholly concealed within the shoe and requires noalteration to the outward appearance of any particular style of shoe.

It is also an object of this invention to provide a device adaptable toany form of shoe which is responsive to pressure placed thereon totransmit a bending force from toe to heel.

In order to facilitate a clear understanding of the invention, theaccompanying drawings illustrate several forms of the said device whichwill carry out the objects of the present invention. In the drawings:

3,039,207 Patented June 19, 1962 FIG. 1 is a side elevation of a shoepartly in section illustrating one form of the invention.

FIG. 2 is a view similar to FIG. 1 illustrating the operation of theshoe.

FIG. 3 is a top plan view of the spring used in FIG. 1 and FIG. 2.

FIG. 4 is a side elevation of a shoe partly in section illustrating asecond form of the invention.

FIG. 5 is a view illustrating the operation of the shoe in FIG. 4.

FIG. 6 is a side elevation in section illustrating another form of thesame invention.

The drawings are intended to illustrate the invention applied todifferent styles or patterns of shoes constructed according to onemethod of manufacture. Certain slight modifications to adapt thisinvention to products manufactured by the various other methods of shoeconstruction will be obvious to those skilled in the art in view of thedescription.

Referring to FIGS. l-3, the type of shoe illustrated is generallyreferred to as a wedge sandal. The straps forming the shoe upper havebeen omitted to simplify the description since they form no part of theinstant invention.

The shoe in these figures has a toe portion I joined to a heel portion 2by a flexible part 3. The toe portion 1 is constructed with an innersole 4 and an outer sole 5 in spaced apart relation. A filler 6 extendsaround the edge of both soles 4 and 5. Filler 6 is resilient andcompressable and may be cemented in place to form a chamber between theinner and outer sole within which is a wave spring 7. Preferably thespring 7 is secured at one end to the toe portion 1 as at 8 and at itsopposite end to the heel portion 9. Any suitable fastening may be used.

Operation Normally the shoe is as shown in FIG. 1. The wave spring 7cannot flatten so long as the heel is flat but as soon as the heel ofthe foot lifts, wave spring 7 begins to compress toward a flattenedcondition. As it is compressed toward a flattened condition it expandsor elongates forcing the shoe to flex at 3 so that the heel of the shoefollows the heel of the foot as it also flexes during each step.

As the weight or pressure is removed from the toe portion as the ball ofthe foot is raised, the shoe returns to the shape in FIG. 1 but sincethe foot also relaxes during this part of the step, the shoe shapes tothe foot throughout the step. 1

In this modification the spring 7 is compressed by the weight of theball of the foot on the inner sole so that the inner sole 4 can betermed a pressure member and the spring 7 an expansible member. It isdesirable that the spring 7 be flexible enough to compress to someextent under the weight of the foot to give a cushion support to theinner sole at all times.

In the shoe shown FIGS. 4 and 5, the toe portion generally indicated as10 is joined to the heel portion generally indicated as 12 by a flexibleportion generally indicated as 13. The heel portion 12 comprises acounter 14 to which is attached a heel 15. The heel 15 and counter 14are reinforced by a shank stiflfener 16 which reinforces the shank ofthe shoe. The exterior of the shank is provided with a sole or cover forthe shank 18 to conceal the steel shank 16. Interiorly of the shoe is acovering 17 for theshank stiflener, usually referred to :as a sockliner, as shown. The cover 18 joins with the outer sole 19, whichextends under the toe of the shoe. Attached to the sole 19 is a vamp 20extending in this instance to the counter 14. Whether either vamp orcounter is present or not, and in what form, depends,

3 of course, entirely upon the style of the shoe, which is not a featureof the present invention.

According to this invention, the shank stiffener 16 extends throughoutthe length of the shank, and where it terminates the sole forms a pocket21 between the toe portion and heel portion of the shoe at the flexibleportion. This pocket will accommodate movement of the shank stiffenerwith respect to the sole of the shoe when the toe portion of the shoe isflexed with respect to the shank portion and heel portion 12 of theshoe. Disposed above the outer sole of the shoe is a composite devicecomprising a wave spring 22 upon which is superposed a spring depressor23 of suitable material which is relatively rigid throughout the soleportion, but is preferable slightly flexible adjacent point 13. Thedepressor 23 and the wave spring 22 are each securely riveted to theshank stiffener 16 at one end by rivet 24 and the spring is secured tothe sole 1h at the opposite end as by rivet 25. A sock liner 17 extendsto the toe and conceals the entire flexing device and the shank so as togive a finished appearance to the inside of the shoe. In the presentconstruction, the rivet 24 approximately coincides With the flexiblepart adjoining the toe portion 10 and the heel portion 12 and acts as afulcrum in the action of the device during operation.

When weight is applied by the foot to the shoe in FIG. 4, the weight atthe toe or at the ball of the foot is cushioned by the wave spring 22and so long as pressure is applied to the heel very little happensexcept for the resilient reaction of the spring 22 to the compressiveweight of the foot which tends to press the shank of the shoe upwardlyso as to lend support to the arch of the foot, thereby adding to thecomfort by increasing the bearing area between the shoe and the foot.However, as soon [as the pressure at the heel of the shoe is removed,the spring 22 will be compressed or flattened, and, as the heel of thefoot lifts during the step, the spring 22 will expand or elongaterelative to the spring depressor 23. The expansion of spring 22 willcause bending of the shoe about a fulcrum point adjacent the rivet 24.Due to the fact that the wave spring is disposed on the underside of thespring depressor 23, deflection will cause the shank stiliener 16 topress upwardly on the shank in a manner to cause the heel of the shoe tolift and follow the heel of the foot as the step is taken and at thesame time produce a lifting force to hold the full length of the shankof the shoe against the arch of the foot.

In order to augment this force creating the bending action as abovedescribed, the shank stiffener has a tip portion 26 which overlaps oneend of the wave spring 22 so that when weight is relieved from the heeland the wave spring 22 is permitted to expand, it will lengthen withrespect to the spring depressor. During expansion the spring 22 will becaused to buckle at the point where it contacts the tip portion 26 ofshank stiffener 16. The buckling action of the spring 22 against the endof the shank stifiener 26 below the fulcrum point determined by therivet 24 will produce a reaction in the opposite end of the shankstiffener in the opposite direction from the application of the force onthe tip portion 26.

The abovementioned reaction to the application of the force from spring22 to tip portion 26 will also aid in lifting the shank stiffener andheel portion of the shoe 12 when the weight is removed. This action isbest illustrated in FIG. 5.

Turning now to FIG. 6, a second modification of the above invention isshown. In this modification the toe portion is again indicated as 10 andthe heel portion indicated as 12. These shoe portions are joined by aflexible portion indicated as 13, similar to that above described.Flexing of one portion of the shoe with respect to the other isaccommodated by the portion 13. In this modification, the shank 27 isformed by a breasting or cover 28 and reinforced by a shank stiffener29. The shank stiffener 29 differs from that above described in that itis provided with an upturned and offset portion 29'. The sole 30 joinsthe breasting or cover for the shank stiflener 28 to form the outersurface of the shoe, and the vamp 20 is attached in some usual manner tothe sole 30. Spaced slightly above the sole 30 near the flexing point 13is a depressor plate 31. The depressor plate may be flexible if desired,and is concealed within the inside of the shoe by the sock liner 32. Apocket is formed between the sock liner 32 and the shank stiffener 29,and this pocket may be filled with a resilient material to form acushion. The shank stiffener 29 has a rib 33 integral therewith forreinforcing purposes, and this rib is notched so as to receive andprovide room for the depressor 31. A member 34 riveted at 35 to shankstiffener 29 and attached to It holds the parts from slipping.

In this modification, the weight of the foot is borne by the depressorplate 31, which, in turn, will exert a force upon the offset end of theshank stiffener 29 which extends forward of the flexing point in portion13 of the shoe. This force will produce a reaction tending to move theshank in an upward direction to lift the heel of the shoe. So long asWeight is on the heel of the shoe, however, this cannot take place, butimmediately after the weight is relieved from the heel of the shoe andtransferred exclusively to the ball of the foot, the action will takeplace lifting the heel of the shoe by the downward force of thedepressor plate against the edge or end 29' of the shank stiffener 29.In this form of the invention the offset 29' may be formed in a mannerto be slightly resilient so that a spring action is effective to producethe lifting force on the heel. In this form FIG. 6 the members 29 and 31act somewhat like the spring 22 on the shank end 26 in FIG. 4.

A device which will carry out the objects of the invention has beendisclosed, but it is contemplated that other modifications of theinvention will occur to those skilled in the art which come within thespirit of the invention as defined in the appended claims.

I claim: A

1. A shoe construction adapted to be effective on the application offoot pressure to exert a lifting force on the heel portion of said shoe,comprising a pair of superposed spaced members in said shoe at least oneof which is flexible, a shank stilfener forming a rigid extension fromsaid heel and having its forward end secured to both of said members toform a fulcrum point with at least one of said members, and aforce-transmitting point of contact with the other of said members in aZone spaced from said fulcrum point.

2. A shoe construction adapted to be effective on the application offoot pressure to exert a lifting force on the heel portion of said shoe,comprising a pair of superposed spaced members in said shoe at least oneof which is flexible and expansible, said heel portion having itsforward end extending in overlapping relation with ad jacent ends ofsaid flexible members at spaced points on said heel portion to formrespectively a fulcrum point with at least one of said members and aforce-transmitting connection with the other said member wherebypressure on said members causes opposite forces to be imposed by saidmembers at said spaced points on said heel portion to produce thelifting action.

3. A shoe construction adapted to be effective on the application offoot pressure to exert a lifting force on the heel portion of said shoe,comprising a pair of superposed spaced flexible members extendinglengthwise of said shoe at least one of which is expansible when pressedtoward the other by foot pressure, a rigid extension from said heelhaving its forward end extending in overlapping relation with adjacentends of said members and attached thereto, and interconnections betweensaid flexible members whereby pressure on said flexible members tendingto force them together causes opposite forces in said members and aresulting force on said extension to produce the lifting action.

4. In a shoe, the combination of a toe portion, a heel portion includingan extension rigid with said heel portion and flexibly connected withsaid toe portion, and superposed spaced apart means connected to saidtoe portion and to an intermediate point in said extension and disposedin overlapping relation adjacent said intermediate point, said meansincluding a part expansible by the pressure of the foot in said toeportion for transmitting a lifting force to said extension adjacent saidintermediate point tending to bend said shoe.

5. In a shoe, a device adapted to be operated by foot pressure toproduce a bending force, tending to lift the heel of the shoe comprisinga first flexible member extending lengthwise of said shoe, a secondflexible member in said shoe longer than said first flexible member andin part coextensive therewith, and means attaching said members to theheel portion of said shoe and to the toe portion thereof with portionsof said members in said toe portion in spaced relation whereby pressureforcing said members together in said toe portion causes a force in onedirection in one of said flexible members and an opposite force in theother of said flexible members to cause a joint deflection in saidflexible members tending to curl up the ends thereof to bend said shoe.

6. In a shoe, having -a sole structure including a toe portion, a heelportion, and a flexible part between said toe and said heel portion, thecombination of a flexible device within said sole structure connectingsaid toe portion and heel portion, including a pair of members securedwith respect to one another, at least one of which is a wave springtensioned when said members are pressed together, to exert a forcelengthwise of said other member tending to cause said flexible device tobend.

7. A device for a shoe adapted to produce a bending force whencompressed, comprising a first flexible member, a second flexible wavespring member in part coextensive with said first member, and means forfixing said members with respect to one another adjacent opposite endswith an intermediate portion thereof in spaced relation whereby pressingsaid members together causes a force in one direction in one of saidflexible members and an opposite force in the other flexible member tocause a joint deflection of said flexible members in the same direction.

8. In a shoe, a pair of superposed flexible members arranged inoverlapping relation lengthwise and extending along the sole portion tothe heel portion of said shoe, one of said members having substantialresistance to forces tending to produce elongation lengthwise thereof,and the other of said members being constructed and arranged to expandlengthwise under foot pressure against the resistance to elongation ofsaid one member to cause bending of both of said members and said shoe.

9. In a shoe, a structure adapted to be eflective on the application offoot pressure in the toe portion to exert an upward force on the footrearwardly of the toe portion, said structure comprising a flexibledevice extending lengthwise of the shoe in the toe portion and heelportion thereof, means in said flexible device for yieldably maintainingparts of said flexible device in spaced relation in said toe portion,said yieldable means tending to expand in one direction when compressedin another direction by foot pressure in the toe portion of said shoe,and means for directing the force produced by expansion upwardly againstthe foot.

10. In a shoe having a toe portion and a heel portion, a structureadapted to be effective on the application of foot pressure in said toeportion to exert an upward force in the heel portion, said structurecomprising a flexible device extending lengthwise of the shoe includinga compressible means in the toe portion of the shoe actuated by footpressure, said compressible means being expansible in one direction whencompressed in another direction by foot pressure in said toe portion,and means in said structure for resisting the expansion of saidcompressible means to produce the resultant upward force in the heelportion of said shoe.

11. In a shoe having a toe portion and a heel portion, a flexible devicein said toe portion acting on said heel portion, said device beingeffective on the application of foot pressure to exert an upward forceon a portion of the foot, said device comprising a flexible structureextending lengthwise of the shoe and including a compressible meansbeing expansible in one direction,

lengthwise of the shoe when compressed by the foot pressure in anotherdirection, and means in said device for resisting lengthwise expansionof said compressible means to produce the resultant upward force on aportion of the foot.

References Cited in the file of this patent UNITED STATES PATENTS741,012 Corey Oct. 13, 1903 880,245 Scholl Feb. 25, 1908 2,691,227 Sachs'Oct. 12, 1954 2,707,342 Maccarone May 3, 1955 2,746,178 Miller May 22,1956 2,761,225 Lo Presti Sept. 4, 1956 2,776,503 Maccarone Jan. 8, 1957FOREIGN PATENTS 487,694 Great Britain June 24, 1938

